infared laser alarm help

[coleio]

hi everyone, over the past few months my grandparents hotel and garage (now closed down) have been victim of a string of breakins, i grew up there and it breaks my heart to see them trashed like they have been, its also taking its toll on my family and my grandad is very unwell!!! i am from ireland and the garda can do absolutely nothing. so this brings me here to ask for your help, when i was in school i took a basic electronics class for a semister and we messed around with a laser circiut that sounded an alarm when broken. this was almost 10 years ago now and i cant remember how it was made/what i needed to make it, and my knowledge of thiss stuff is very poor, can anyone help provide the info i need to make a infared laser alarm circiut that sounded an alarm or if possible rang a phone number when broken!! i have a budget of about 800 euro and i know this is a big ask and alot of you will think im being stupid but i only need a point in the right direction!! so please help. i am looking forward to your reply

 

[ericgibbs]

hi,
You can get mains powered PIR sensors/lamps in one housing, also some types have an indoor plug in 'ding dong' unit that sounds when the PIR detects an intruder.

 

[Joe G]

i used a motion sensor off of an outside security light from a department store, used an alarm speaker from a forklift, powered by a cellphone type charger into the other
light fixture , this way i had a light and alarm for storage shed, everything was found so the cost was nothing but my time. i didn't have anything taken again.

 

[Ross Craney]

I'm not sure what 800Euros equates to but you should be able to buy a complete basic ( 4 zone ) alarm package for about 180 pound (guessing) & install yourself if you have the capabilities. If access around the building for cabling is restricted then a QUALITY wireless system may be the way to go but the price would near double. I'd stay away from security light sensors to operate an alarm as their discrimination capabilities are close to zero. Modern alarm PIRs have a huge amount of analytical circuitry in them